Multi-viscosity printer ink

ABSTRACT

A printing ink for use within multiple ambient temperatures which comprises a mixture of two or more inks having different viscosities at a given temperature. Thus, one or more lower viscosity inks having, for example, a viscosity in the range of about 300 cps to about 900 cps is mixed with one or more higher viscosity inks having, for example, a viscosity range of about 1100 cps to about 1800 cps to provide a multi-viscosity ink mixture useful over a wide temperature range. A print ribbon which carries the multi-viscosity ink mixture and, the combination of an impact printer incorporating said print ribbon are provided. A method for printing with an ink mixture to compensate for varying ambient temperatures includes the steps of mixing together two or more inks each having a different viscosity at the same given temperature to form an ink mixture; and, printing with said ink mixture on a medium to be printed upon.

[0001] This application claims the benefit and priority of U.S.Provisional Application Serial No. 60/411,959; filed Sep. 19, 2002;entitled: MULTI-VISCOSITY PRINTER INK; Applicants: Jeng-Dung Jou,Irvine, Calif. 92620, Dennis R. White, Fountain Valley, Calif., andGordon B. Barrus, San Juan Capistrano, Calif.

[0002] Your Petitioners, Jeng-Dung Jou, a citizen of Taiwan and aresident of Orange County in the State of California whose residence andpost office address is: 19 Mount Vernon, Irvine, Calif. 92620; Dennis R.White, a citizen of the United States of America and a resident ofOrange County in the State of California whose residence and post officeaddress is: 11561 Azalea Avenue, Fountain Valley, Calif. 92708; andGordon B. Barrus, a citizen of the United States of America and aresident of Orange County in the State of California whose residence andpost office address is: 31516 Paseo Christina, San Juan Capistrano,Calif. 92675, pray that letters patent may be granted to them for theinvention of A MULTI-VISCOSITY PRINTER INK as set forth in the followingSpecification.

BACKGROUND OF THE INVENTION

[0003] The background of this invention resides within the field ofprinter inks and printing systems. In particular, it resides in thefield of printer inks which are utilized for various applications suchas with printer ribbons or other printing ink applications. Morespecifically it resides within the field of systems for impact printersand inks which cooperate to provide printing with the aid of a printribbon.

PRIOR ART

[0004] Viscosity for an ink is a measure of the ink's thickness. Lowviscosity printer ink loses shear strength at high temperatures evenwhen disposed on a carrier such as a printer ink ribbon. Within impactprinting applications such as those using an ink ribbon, this can resultin ink smearing and ink migration. This lowers the print quality.

[0005] On the other hand, the viscosity of an ink that performs well atelevated temperatures becomes excessively high as to its viscosity atlower temperatures. Excessively high ink viscosity exhibits otherprinting problems. The problems can include poor transfer into and outof the printer ribbon, resistance to pumping through small tubing, and avery slow transfer through foam materials. Such foam materials can beused in an ink reservoir roller to replace ink within the printerribbon.

[0006] An ideal printer ink should flow easily when the ambienttemperature is cold. The ideal ink should also remain thick enough sothat it will not excessively migrate when the temperature is hot. Lowambient temperatures require a light (i.e. low viscosity) ink and hightemperature requires a heavy (i.e. high viscosity) ink.

[0007] Viscous flow as to ink can be pictured as taking place by themovement of molecules or segments of molecules from one place in alattice to a vacant hole. The total “hole” concentration can be regardedas a space free of polymer or free volume (Rodriguez, F., Principles ofPolymer Systems, 3:177, 1989). Doolittle proposed (Doolittle, A. K., J.Appl. Phys., 22:1471, 1951) that the viscosity should vary with the freevolume and free volume is expected to vary with temperature. Thediffusion and movement is closely related to the size of a moleculerepresented by the hydrodynamic volume.

[0008] Low temperatures are favorable to small molecule movement whereashigh temperatures are conducive to the movement of either small or largemolecules. Thus when inks having small molecules are exposed to hightemperatures they move with great freedom. Inks having large moleculescan also move freely at high temperatures but not as freely as withsmall molecules, and not effectively at low temperatures.

[0009] It has been found according to the invention that when both smalland large molecules are mixed together, they intermingle so that thesmaller molecules are carried along with the larger molecules. Thiscauses a synergistic property wherein the combined fluid acts more likethe small molecules at lower temperatures and the large molecules atelevated temperatures.

[0010] This invention establishes that a mixture of two or more inks ofdifferent viscosities form multi-viscosity inks wherein the highmolecule-weight spread (i.e. high poly-dispersity) performs well at afull temperature range in which print systems such as impact printersare expected to operate. These multi-viscosity inks remain sufficientlyviscous at elevated temperatures, while maintaining a lower-than-normalviscosity at lower temperatures.

SUMMARY OF THE INVENTION

[0011] In summation, this invention comprises a blended, multi-viscosity(MV) ink mixture for printing applications, yielding a more consistentviscosity throughout the operational temperature range expected ofindustrial impact printers.

[0012] More particularly, the invention utilizes an ink formulation thatincorporates two or more mono-viscous ink components, combined in ratiosto produce a united multi-viscosity ink. The lower viscosity inks orcomponents influence the combination by lowering its “apparentviscosity” at lower operating temperatures. The higher viscosity inks orcomponents influence the combination by maintaining sufficient viscosityfor printing applications at the higher end of operating temperatures.The net effect is that the “apparent viscosity” remains more nearlyconstant across the printer's operating temperature range, than is thecase with single or mono-viscosity inks.

[0013] Using multi-viscosity ink mixtures in impact or other printingtechnologies improves printing results. It helps to reduce or eliminatethe propensity for ink smearing on the print media and ink migrationinto the printing mechanism at high temperatures. It also helps tomaintain print density and ink distribution in an ink ribbon at lowertemperatures.

[0014] Inks are primarily composed of pigments, vehicles andsupplementary additives. Pigments are finely divided solid materialsthat give inks color and opacity or transparency. The function of thevehicle is to act as a carrier and as a binder to affix the pigment tothe printed surface. The nature of the vehicle determines in a largemeasure the tack and flow characterization including viscosity.Supplementary additives include among others lubricants which act toinfluence flow characteristics, and dyes which impart ink color.

[0015] A method for printing with an ink mixture to compensate forvarying ambient temperatures is also provided which includes mixingtogether two or more inks each having a different viscosity modulus toform an ink mixture; and, printing with said mixture on a medium to beprinted upon.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 shows a graph of viscosity versus temperature on alogarithmic scale for a 50/50 by volume mixture of inks, one ink havinga viscosity of 750 cps and one ink having a viscosity of 1600 cps ascompared with each single or mono-viscosity ink.

[0017]FIG. 2 shows a graph of a viscosity comparison of a singleviscosity ink of 1050 cps and a 50/50 by volume ink mixture of an inkhaving a viscosity of 750 cps and an ink having a viscosity of 1600 cps.

[0018]FIG. 3 shows a graph on a logarithmic scale of viscosity versustemperature for a 50/50 mixture and a 70/30 mixture of an ink having aviscosity of 750 cps and an ink having a viscosity of 1600 cpsrespectively.

[0019]FIG. 4 shows on a logarithmic scale two different mixtures of lowviscosity inks combined in the same volume proportions with the samehigh viscosity ink.

[0020]FIG. 5 shows a perspective view of a fragmented portion of animpact printer having a print ribbon which can use the ink of thisinvention.

[0021]FIG. 6 is a fragmented perspective view showing a hammerbank,platen, and the associated portions in the direction of lines 6-6 ofFIG. 5.

[0022]FIG. 7 is a sectional view in the direction of lines 7-7 of FIG.6.

[0023]FIG. 8 is a fragmented perspective elevation view of thehammerbank and print hammer details.

[0024]FIG. 9 is a sectional view in the direction of lines 9-9 of FIG. 6showing the magnetics and hammers of the impact printer of thisinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Looking more specifically at FIG. 5, it can be seen that aprinter 10 is shown having spindles or hubs 12 and 14.

[0026] The hubs 12 and 14 receive respectively spools of print ribbon 16and 18. The ribbon in these respective spools moves forwardly andbackwardly across the face of a number of hammers on a printerhammerbank facing the print ribbon 20 that is wound around the spools 16and 18.

[0027] In order to support paper, a paper support 26 is shown with asplined shaft 24 and knob 28 to advance paper along a tractor.

[0028] Looking specifically at FIG. 6, it can be seen that a hammerbankportion of the impact line printer in the form of a fragmented segmenttoward the end of the hammerbank is shown. The fragmented portion of thehammerbank is a segment that is cut from an elongated hammerbank havingapproximately anywhere from forty to one hundred print hammers more orless. The print hammers can be retained and then fired or releasedagainst a print ribbon as is well known in the art.

[0029] The hammerbank 50 is such wherein the base or shuttle isgenerally machined or cut from an elongated metal portion such as analuminum casting or extrusion. It can be formed in any other suitablemanner to provide for an elongated mounting of the hammers on thehammerbank. In this particular case, it can be seen that the hammerbankhas a rear channel area 52 which can receive an elongated circuit boardor other controlling means such as in U.S. Pat. No. 5,743,665 Entitled aPrinter Integrated Driver and Hammerbank dated Apr. 8, 1998 namingRobert P. Ryan and Gordon Barrus as inventors. The hammerbank 50 has anelongated channel or groove 54 which receives a permanent magnet as willbe described hereinafter.

[0030] As is customary in line printer hammerbanks, they can comprise aseries of hammers 56 connected to and formed on a fret 58. The fret 58is secured to the hammerbank by screws, nuts or bolts or any othersecurement means shown generally as screws 60.

[0031] As detailed in FIG. 9, the hammers 56 comprise an enlargedportion 66 to which a pin 68 is welded, brazed or otherwise connectedthereto. The enlarged portion 66 terminates in a necked down springportion 70 connected to and formed with the fret 58. This entirestructure and shape of the hammers 56 can be configured in othersuitable manners to allow for the dynamics of printing as is understoodin the art.

[0032] As seen in FIGS. 8 and 9, each pin 68 has a reduced tip 80. Thereduced tip 80 is the portion that is impacted against the ribbon 20.This forms a dot matrix printing array, pattern, alpha numeric symbols,Oriental style lettering, a particular pattern, or pictorialrepresentation.

[0033] In order to retain the hammers 56 which are sprung for printingmovement away from the hammerbank, a permanent magnetic force is appliedthrough a pair of pole pins, pole pieces, or pole members which providethe magnetic circuit. These terminate in upper and lower pole piecetermination sections, hammer contacts, terminals or pins, 84 and 86.These pole piece terminal portions 84 and 86 are generally provided witha surface 88 therebetween against which a hammer 56 can be retracted andcreates an impact or wear surface.

[0034] Looking more particularly at FIG. 9 the terminal points ormagnetic contact portions of the pole pieces 84 and 86 are shown withtheir pole pieces 92 and 94. The pole pieces 92 and 94 are wound withwire coils 96 and 98.

[0035] In FIGS. 8 and 9 it is seen that a retention magnet 100 is shown.The magnet 100 allows for the magnet to be placed in the channel 54against the rearward ends of the pole pieces 92 and 94. The pole pieces92 and 94 allow placement of the magnet 100 there against to provide inturn for a magnetic circuit through the pole pieces 94 and 96.

[0036] The leads and terminals 119 and 121 are utilized to allow forconduction of a driving voltage to the respective coils 96 and 98 aroundpole pieces 92 and 94.

[0037] The hammerbank fret 58 terminates in the upwardly projectinghammers 56. The hammers 56 have the attendant enlarged portions 66 andnecked down intermediate portions 70 serving a dominant spring functionwith the pins 68 having the striking portions or tips 80.

[0038] The foregoing configuration as to the pole pieces 92 and 94, andthe magnet 100, are potted.

[0039] Looking more specifically at FIGS. 6 and 7, it can be seen thatthe operational aspects of the line printer are shown with paper orother media 140 passing there through. The hammerbank 50 has beenfragmented to show the attachment of the cover thereon.

[0040] The fret 58 and the attendant hammer 56 has been shown in FIG. 7in a dotted configuration along with the tip 80 extending therefrom. InFIG. 7, the details are more pronounced in the cross-section. Theprinter includes a platen 122 with a platen adjustment extension 124which provides for the rotation of the platen in and out of theoperating position.

[0041] Looking more particularly beyond the cover 120 and the respectivehammers 56 that are therebehind, it can be seen that the ribbon 20 isshown. The ribbon 20 is the one impacted by the tips 80 of the hammers56. The tips 80 extend through the openings 128.

[0042] Between the ribbon 20 and the paper or media 140 to be printed onis a ribbon mask 130. This ribbon mask 130 is such wherein it providesfor masking of the print from the entire ribbon 20. This helps toeliminate print ribbon smear and ink being spread in an unwanted manneras the hammer tips 80 pass through the openings 136 of the mask 130. Thepaper or media 140 passes over the platen face 142 of the platen 122.This allows the hammers 56 when released to be impacted against theribbon 20 and attendantly cause printing on the underlying media orpaper 140.

[0043] The cover 120 incorporates the hammer tip openings 128 in aplural line of openings along the length thereof. This allows for thetips 80 of the hammers 56 to extend therefrom and provide an impact uponthe paper or underlying media 140 on the opposite side of the mask 130.

[0044] As can be appreciated from the foregoing description with regardto a line printer such as that shown in FIGS. 6 through 9, it can beseen that ink when placed on the print ribbon 20 would have a chance formigration if it can readily flow. This is based upon not onlygravitational forces but also merely the aspects of movement and impactof the ink ribbon 20.

[0045] In order to compensate for this, it has often been necessary todisadvantageously use overly viscous or light inks in order tocompensate for ambient temperatures. As can be appreciated, if theambient temperature were not correct, the ink would either be gummy onthe ribbon 20 or flow excessively.

[0046] Looking more particularly at FIGS. 7, 8, and 9, it can be seenthat ink from the print ribbon 20 when placed thereon could gravitateand smudge through the openings 136 against the media 140 that is to beprinted upon. It becomes particularly apparent when considering the factthat the hammer pins 68 with the hammer tips 80 when striking the ribboncause greater migrational flow of the ink. Further to this extent, theink tends to flow more rapidly in high ambient temperatures. Of course,in low ambient temperatures the lighter or less viscous ink on theribbon 20 would be to an advantage because of the fact that it wouldn'tflow as readily.

[0047] This invention allows for more controlled flow of the ink fromthe ribbon 20 against the media 140. It helps to prevent smudgingthrough the openings such as opening 136 or on the mask 130. The inkmixture of this system functions to substantially diminish many of theproblems in the prior art of such impact printers.

[0048] In FIG. 1, based upon a logarithmic scale, the multi-viscosityink mixture consists of inks of high and low viscosity mixed together.This produces a hybrid ink mixture with synergistic properties. Theforegoing example utilized a mixture containing 50% by volume of an inkhaving a low viscosity of 750 cps and 50% by volume of an ink having ahigh viscosity of 1600 cps at room temperature. For purposes of thisapplication with respect to the given viscosities, room temperature isdefined as 25° C. A 50% mixture by volume was chosen in order todetermine whether the resultant viscosity would exhibit a proportionalrelationship to the constituent viscosities. If so, then the resultantviscosity curve would lie equidistant from the constituent curves.

[0049] From the results, it was found that low temperature is notdetrimental to small molecule movement. High temperature is conducive tothe movement of either small or large molecules. The resultant effect onviscosity was not proportional to the percentage of the mix. Forinstance by adding an equal amount of high viscosity ink (for example50%) to an amount of low viscosity ink (for example 50%), adisproportional effect in a low ambient temperature was found. Theresulting “apparent viscosity: exhibits high temperature viscosity onlyslightly lower than the high viscosity constituent, yet significantlylower viscosity at low temperatures, than the high viscosityconstituent.

[0050]FIG. 2 shows a viscosity comparison between a multi-viscosity inkmixture and a single viscosity ink. The multi-viscosity ink mixturesconsists of equal parts by volume of an ink having a viscosity of 750cps and an ink having a viscosity of 1600 cps. The single ormono-viscosity ink has a viscosity of 1050 cps.

[0051] The graph of FIG. 2 shows that a multi-viscosity ink mixture canimprove the flow conditions at cold temperatures and maintain the sameproperties as single viscosity inks at room temperature and highertemperatures. However, other viscosities may be preferred and can beformulated for use in varying printing temperatures.

[0052] Viscosity studies have been conducted for inks with differentpigment loads within the temperature range of 5° to 40° C. A preferredor idealized viscosity range was found to be around 1000 cps at roomtemperature. If the viscosity is too low at room temperature, it cancause ink smearing and ink migration at hot temperatures (40° C.).

[0053] From the data of FIG. 2, the multi-viscosity (MV) ink mixture canmaintain ideal apparent ink viscosity at ambient room to hightemperatures in comparison with uni-viscosity inks. This applies to bothdye-based ink and pigmented ink.

[0054] In addition as seen in FIG. 2, the “apparent” (or “MV”) inkviscosity is 3000 cps lower than uni-viscosity inks at 5° C. Thetemperature range (5° C. to 40° C.) within which the experiments wereconducted corresponds to standard operational temperatures of manyprinters. In order to predict viscosity beyond this range, the followingequation is helpful:

ln(μ)=A−B T  (1)

[0055] The viscosity μ is given in centipoises and the temperature T isexpressed in Celsius. The coefficients, A and B in the equation aredetermined from regressing experimental ink-viscosity data. The equationcan be used to anticipate results at temperatures beyond the limits ofthe experiments. The equation itself is limited in scope. Any viscousliquid, blended or not, will exhibit linear behavior (in logarithmicscale) only within some practical range. The actual limits of linearitywill be dependent upon a particular material's characteristics.

[0056]FIG. 3 shows the comparison of two different multi-viscosity inkmixtures or combinations. The high viscosity ink has a viscosity of 1600cps at room temperature. The low viscosity ink has a viscosity of 750cps at room temperature.

[0057] The ink designated “Viscosity (50/50)”: 50% by volume is amixture of a Low viscosity ink of 750 cps and 50% by volume of a Highviscosity ink of 1600 cps.

[0058] The equation for viscosity (50/50) pertaining thereto is:

ln(μ)=8.4−0.0593 T  (2).

[0059] The ink designated “Viscosity (70/30)”: 70% by volume is amixture of Low viscosity ink of 750 cps and 30% by volume high viscosityink of 1600 cps.

[0060] The equation of viscosity (70/30) pertaining thereto is:

ln(μ)=8.0−0.0563T  (3).

[0061] From regressing equations, the ink combination (70/30) flattensthe slope of the curve 5% and the intercept declines 5% in a logarithmicscale in comparison with a 50/50 by volume mixture.

[0062]FIG. 4 shows a logarithmic graph of viscosity versus temperaturefor two different multi-viscosity ink mixtures in a 50% to 50% ratio byvolume. One mixture incorporates a low viscosity ink of 550 cps with ahigh viscosity ink of 1600 cps. The other mixture incorporates a lowviscosity ink of 750 cps with a high viscosity ink of 1600 cps. Thisdiagram illustrates that by varying the viscosity values, and mixturepercentages, it is possible to tailor a multi-viscosity ink mixture tooptimize ink performance for a particular application.

[0063] While the examples shown and described herein illustrate amixture of two inks of different viscosities it should be understoodthat the invention is not limited to a mixture of two inks of differentviscosities but is intended to include mixtures of two or more inks ofdifferent viscosities. For example, three or more inks of differentviscosities can be selected based on the particular mono-viscosity ofeach ink forming the ink mixture so that the ink mixture can be tailoredto provide a multi-viscosity ink mixture which would be particularlyuseful over a given temperature range. The given temperature ranges ofmore than two monoviscosity inks when mixed can be temperature specific.For example if a printer is to be used in a warehouse, a heatedindustrial area, and an office interchangeably, the ink can becompounded to accommodate the three or more given ambient temperatures.As a further example, some line printers are now moved from oneenvironment to another, which changes the relationship of the ambienttemperature. Using the two or more ink compounds of this invention cancause the ink to be temperature specific and perform in an improved waywith respect to each ambient temperature.

[0064] In summation it has been found that an optimum blend of two,three or more inks having different viscosities can be made for use inimpact printing applications such as line printing, and within othertypes of printers. The resulting product is a synergisticmulti-viscosity blend that performs well throughout the temperaturerange anticipated in many applications. Other factors that influence theactual percentages of the different viscosity inks used to optimize theblend include, but need not be limited to the presence or absence ofadditives and pigments and the type of media to be printed upon.

[0065] Various modifications of the invention are contemplated whichwill be obvious to those skilled in the art and can be resorted towithout departing from the spirit and scope of the invention as definedin the following claims.

1. A printing ink for use in multiple temperatures comprising: a mixtureof two or more inks each ink having a different viscosity at the samegiven temperature.
 2. The printing ink as claimed in claim 1 furthercomprising: one or more inks having a lower viscosity at apre-determined temperature mixed with one or more inks having aviscosity at said pre-determined temperature which is higher than saidone or more inks having a lower viscosity.
 3. The printing ink asclaimed in claim 2 further comprising: said one or more inks having alower viscosity in said mixture comprises from about 30% to about 70% byvolume of said mixture; and, said one or more inks having a higherviscosity in said mixture comprises from about 70% to about 30% byvolume of said mixture.
 4. The printing ink as claimed in claim 1wherein: said one or more inks having a lower viscosity comprises asingle ink having a lower viscosity which comprises at least about 30%by volume with the balance by volume comprising said one or more inkshaving a higher viscosity.
 5. The printing ink as claimed in claim 1wherein: said one or more inks having a higher viscosity comprises asingle ink having a higher viscosity which comprises at least about 30%by volume with the balance by volume comprising said one or more lowerviscosity inks.
 6. The printing ink as claimed in claim 1 wherein: saidmixture comprises one lower viscosity ink and one higher viscosity ink.7. The printing ink as claimed in claim 1 wherein: said one or morelower viscosity inks has a viscosity in the range of about 300 to about900 cps; and, said one or more higher viscosity inks has a viscosity inthe range of about 1100 to about 1800 cps.
 8. The printing ink asclaimed in claim 1 wherein: said one or more lower viscosity inkscomprises from about 30% to about 70% by volume of said mixture; saidone or more higher viscosity inks comprises from about 30% to about 70%by volume of said mixture; the viscosity of said one or more lowerviscosity inks is within the range of about 300 cps to about 900 cps;and, the viscosity of said one or more higher viscosity inks is withinthe range of about 1100 cps to about 1800 cps.
 9. The printing ink asclaimed in claim 1 wherein: said one or more lower viscosity inkscomprises about 50% by volume of said mixture; and, said one or morehigher viscosity inks comprises about 50% by volume of said mixture. 10.The printing ink as claimed in claim 1 further comprising: a printribbon on which said printing ink is carried.
 11. The printing ink asclaimed in claim 10 further comprising: an impact printer incorporatingsaid ribbon with said ink; a series of hammers with tips for impactingsaid ribbon; a permanent magnet for retaining said hammers; and, anelectrical drive for overcoming the retention of said hammers andcausing said printing tips to impact said ribbon and print on anunderlying medium.
 12. A printing system comprising: an impact printerhaving printing tips supported on a plurality of hammers on ahammerbank; at least one permanent magnet for retaining said hammers; anelectrically driven coil for overcoming the permanent magnetismretaining said hammers; a printer ribbon placed for impact by saidprinting tips against a medium to be printed upon; and, an ink mixturedisposed on said ribbon comprising a mixture of two or more inks eachink having a different viscosity at a given temperature.
 13. Theprinting system as claimed in claim 12 further comprising: a mask withopenings for said printer tips; a platen for supporting the medium to beprinted upon; and, wherein said hammers form a hammerbank of a lineprinter.
 14. The printing system as claimed in claim 12 furthercomprising: said ink mixture comprises one or more inks having a lowerviscosity at a pre-determined temperature mixed with one or more inkshaving a viscosity at said pre-determined temperature which is higherthan said one or more inks having a lower viscosity.
 15. The printingsystem as claimed in claim 12 further comprising: said one or more inkshas a lower viscosity at a pre-determined temperature which comprisesfrom about 30% to about 70% by volume of said mixture; and, said one ormore inks has a higher viscosity at said pre-determined temperaturewhich comprises from about 30% to about 70% by volume of said mixture.16. The printing system as claimed in claim 15 wherein: said one or moreinks of said mixture having a lower viscosity has a viscosity in therange of about 300 cps to about 900 cps; said one or more inks of saidmixture having a higher viscosity has a viscosity in the range of about1100 cps to about 1800 cps; and, said one or more lower viscosity inksand one or more higher viscosity inks each comprise about 50% by volumeof said ink mixture.
 17. A print ribbon with ink for an impact printercomprising: a print ribbon formed of an absorbent material which retainsink in its interstices; and, an ink mixture disposed on said ribboncomprising two or more inks each ink having a different viscosity at thesame given temperature.
 18. The print ribbon with ink as claimed inclaim 17 further comprising: one or more inks having a lower viscositywithin the range of about 300 cps to about 900 cps at 25° C.; and, oneor more inks having a higher viscosity is within the range of about 1100cps to about 1800 cps at 25° C.
 19. The print ribbon with ink as claimedin claim 18 wherein: said one or more inks having a lower viscositycomprises from about 30% to about 70% by volume of said ink mixture;and, said one or more inks having a higher viscosity comprises fromabout 30% to about 70% by volume of said ink mixture.
 20. A method forprinting with an ink mixture to compensate for varying ambienttemperatures comprising: mixing together two or more inks each having adifferent viscosity at the same given temperature to form an inkmixture; and, printing with said mixture on a medium to be printed upon.21. The method as claimed in claim 20 further comprising: mixingtogether one or more inks having a lower viscosity at a predeterminedtemperature with one or more inks having a higher viscosity at the samepredetermined temperature to form an ink mixture; disposing said inkmixture on a print ribbon; striking said print ribbon with printingelements to impact said ribbon and dispose said ink mixture on saidmedium.
 22. The method as claimed in claim 21 further comprising:passing said print ribbon between two spools across said printingelements formed of printing tips.
 23. The method as claimed in claim 21wherein: said one or more inks of said ink mixture having a lowerviscosity has a viscosity in the range of about 300 cps to about 900cps; and, said one or more inks having a higher viscosity has aviscosity in the range of about 1100 cps to about 1800 cps.
 24. Themethod as claimed in claim 21 wherein: said one or more inks having alower viscosity comprises from about 30% to about 70% by volume of saidink mixture; and said one or mor inks having a higher viscositycomprises from about 30% to about 70% by volume of said ink mixture. 25.A method of printing in varying ambient temperatures comprising:providing a printer having a plurality of hammers with printing tips ona hammerbank; providing a permanent magnet for retaining said hammers;releasing said hammers with electric magnetism to overcome the force ofsaid permanent magnet; and, passing a print ribbon having an ink formedof a mixture of two or more different viscosity inks across said hammertips for printing on a media.
 26. The method as claimed in claim 25further comprising: masking said print ribbon with a printing maskhaving openings receiving said printing tips.
 27. The method as claimedin claim 25 further comprising: forming said ink mixture from said oneor more lower viscosity inks having a viscosity in the range of about300 cps to about 900 cps at 25° C.; and, said one or more higherviscosity inks having a range of about 1100 cps to about 1800 cps at 25°C.
 28. The method as claimed in claim 25 further comprising: formingsaid ink mixture with two different single viscosity inks, each inkcomprising from about 30% to about 70% by volume.